In-vitro studies with elvucitabine have shown that HIV-1 isolates with the M184V mutation show only a 10-fold increase in IC50 as compared to wild type HIV-1. Achillion Pharmaceutical's intention is to demonstrate that 10 mg of elvucitabine, administered once per day for 14 days with continued background anti-HIV-1 medications, will demonstrate a fall in HIV-1 RNA plasma levels, as compared to baseline. The data from this study will guide dosing in future long-term studies in HIV-1 infected patients with the M184V mutation.